Sharon Bialek arrives for her news conference in New York today where she accused Republican presidential candidate Herman Cain of making an unwanted sexual advance against her in 1997. She said she wanted to provide "a face and a voice" to support other accusers who have so far remained anonymous. (AP Photo/Richard Drew)

Herman Cain’s candidacy has reached “a tipping point,” one Iowa conservative leader said Monday, as some Republicans here reacted with distaste to fresh allegations about inappropriate behavior — from a fourth accuser who isn’t anonymous.

The Des Moines Register re-interviewed 15 conservative Iowans who participated in the Iowa Poll two weeks ago, and 11 of them said Sharon Bialek’s detailed allegations about Cain groping her in 1997 are troubling enough to at least make them question the retired restaurant executive’s fitness for the White House.

Cain was 31-year-old Sioux City resident Joe Sandvick’s top choice in the Iowa Poll, but on Monday, Sandvick said the new claims draw the candidate’s character into question “dramatically.”

“If there’s one allegation, that’s one thing. When there’s two, there’s smoke. And when there’s three or four, then you’ve got a full-blown fire,” said Sandvick, a tea party supporter. “Usually if you’ve got that many people coming forward, it’s got to be somewhat true somewhere along the line. They can’t all be in cahoots and say it’s a conspiracy.”

Some of Cain’s Iowa backers, including Pottawattamie County GOP Chairman Jeff Jorgensen, immediately came to Cain’s defense.

But other Iowa conservatives said the fact that Bialek identified herself and gave an on-the-record account of an alleged groping incident is a game-changer.

Bob Vander Plaats, president of the Family Leader, a conservative organization that promotes Christian values, said Cain needs to address these allegations head-on, or a “cloud of doubt will envelop his candidacy.”

“The Iowa and American voter are fair when humility, sincerity and authenticity are communicated. This is a tipping point for the viability of his campaign,” Vander Plaats said.

Longtime Republican strategist Doug Gross of Des Moines summed up his reaction to Bialek’s description of the events with one word: “Yuck.”

Steve Scheffler, head of the Iowa Faith & Freedom Coalition, advised Cain to be forthcoming.

“Denying some of the charges and then sometimes later saying he remembers some of the facts is not helpful,” Scheffler said.

Cain backer: ‘Can we trust this man’?

Minister’s wife Donna Riley, 39, of Logan, who picked Cain as her top choice in the October Iowa Poll, said last week she would continue to support Cain. But on Monday, she said the allegations of physical harassment are worrisome.

“When the man says nothing happened, or it was nothing big, well, this sounds a little bigger than that,” said Riley, a born-again Christian. “I still like a lot of his stuff, but it does show, ‘How can we trust this man?’”

Riley said she wants Cain to explain in detail what happened with Bialek. “If he did it, just be truthful about it.”

Leslie Bockenstedt, 43, of Dyersville, who identified herself as very conservative in the Iowa Poll, said Monday that it was courageous for Bialek to come forward in a news conference that aired live on CNN.

“It gives it a little bit more clout that she was willing to do that,” Bockenstedt said. “But you have to weigh out both sides — is this a witch hunt?”

She also said, “If there’s any fragment of truth to those allegations, that’s not the kind of professional person that I would want sitting in the White House.”

Meanwhile, some other Cain backers seemed unperturbed.

Jorgensen, chairman of the Pottawattamie County central committee, said he still backs Cain wholesale.

With all the accusations flying around, Jorgensen said, he still hasn’t heard “very credible evidence.”

“If it was proven in a court of law, that’s relevant,” he said. “But this hearsay — no witnesses, he said/she said kind of stuff, that could go on forever and not prove anybody’s point.”

Lawyer: Accusers fear retaliation

Des Moines lawyer Matt Brick, who practices employment law, including sexual harassment cases, said juries deal with evidence every day where there are no witnesses or proof other than testimony from the two people involved.

“It’s just a simple matter of credibility,” he said. “I think most juries in Iowa would find it interesting if people are saying that with just he said/she said evidence, they can’t rule one way or another on whether someone is liable or not liable of discrimination or harassment.”

Des Moines lawyer Roxanne Conlin, an expert on sexual harassment cases, said there’s often a pattern of harassment. And most victims don’t report being sexually harassed.

“The reason they don’t is they fear retaliation. They fear not being believed and they fear making it worse,” she said. “Three-quarters of those who do report do suffer retaliation.”

Conlin noted that when two women who worked for the National Restaurant Association and filed internal complaints against Cain, their harassment allegations were handled with financial settlements and confidentiality agreements.

“He kept his job. What happened to theirs? They lost their job,” Conlin said.

Poll respondent Ann Barker, 63, of Sioux City, a cook at a private school, believes Cain. She scoffed at the allegations.

“If you really think about it, they tried three ladies, and that didn’t work, the polls were still the same, so they said, ‘We’ve got to come up with something extra.’ When you think about exactly how she explained it, it’s really not believable.”

Staffer: Don’t rush to judgment

“Iowans need to take a look at where Herman Cain stands on the issues and measure that against what our country needs,” Steve Grubbs said in a telephone interview. “Fifteen years ago there was an opportunity to learn the facts. That opportunity passed, and it’s unfair to try a candidate in the court of public opinion when the details are that old.”

Cain hired Grubbs, a Davenport-based political consultant and former state GOP chairman, last month to head his Iowa campaign after a series of well-received debate performances pushed him to the top of national polls.

“As the chair of the campaign, I would ask Republicans to give us some time and watch what Herman Cain says and does moving forward, and I’m confident they will like what they see,” Grubbs said.